PINCH S. and HENRY N.(1999) Paul Krugman’s geographical economics, industrial clustering and the British motor sport industry, Reg. Studies 33, 815±827. Paul Krugman is one of a growing band of economists who have discovered the importance of the region in stimulating national economic competitiveness. Whilst the early reactions to his ideas by geographers tended to be hostile, there have recently been calls by geographers for a more considered view of his concepts. This paper examines the utility of Krugman’s ideas for explaining the geographical cluster of small® rms constituted by the British motor sport industry. It is argued that Krugman’s emphasis upon accidents of history and external economies of scale provides only partial insights into the reasons for the evolution and maintenance of this industrial agglomeration. Greater insights are provided by an approach which focuses upon the dissemination of knowledge through the concept of untraded interdependencies.